1. Field of the Invention
This invention relates to the restoration industry, in general, and to the drying-out of water damaged buildings, in particular.
2. Description of the Related Art
As is well known and understood, many factors can adversely affect the indoor air quality of buildings, but nothing is as threatening to the indoor environment as water intrusion. As is also well known, when water damage occurs—be it as a result of a burst pipe, a leaky roof or windows, or a flood—it becomes essential to take immediate action. Otherwise, the contents of vital records can be ruined, operations can be disrupted, tenants can be displaced, rental income can be negatively impacted and such irreparable damage can be done as to result in costly repairs or even total loss. As is more and more being appreciated, the moisture can also feed mold growth—which, in itself, is such an onerous threat as to which no building becomes immune.
As is additionally well known and appreciated, water intrusion often occurs without warning—for example, as a result of hurricane flooding, when pipes burst (frequently in the middle of the night or when no one is around), or when roof air conditioning systems fail.
When water intrusion of this sort occurs, a professional disaster restoration services provider is summoned to immediately take action to stabilize the environment, mitigate loss, and preserve good indoor air quality. After first quickly identifying “totalled” contents and removing them from the building, the next step is to dry the air using dehumidification systems specifically engineered for that purpose. In particular, the use of dessicant dehumidification systems has grown in popularity as the most effective water abatement technology due to their ability to create low relative humidity and dew point temperatures inside a structure. Unlike cooking-based dehumidifiers (which cool the air to condense moisture and then draw it away), dessicants attract moisture molecules directly from the air and release them into an exhaust air stream. Able to attract and hold many, many times their dry weight in water vapor, such dessicants are very effective in removing moisture from the air at lower humidity levels, and do not freeze when operated at low temperatures.
As described in my U.S. Pat. No. 6,652,628 (which issued Nov. 25, 2003), mobile dessicant dehumidifiers have begun to be employed more and more in recent years to dry water damaged buildings to reduce health problems caused by the incipient mold which develops. As is there noted, silica gel is oftentimes employed as the dessicant in a wheel through which the moistened air is pulled from the walls, the floor, the concrete, etc. into the dehumidifying chamber. As the silica gel absorbs the moisture, it became necessary to additionally heat the dessicant to liberate the moisture it collects. Where large scale dessicant equipment is employed, the heat energy required is typically provided by electric heating or propane heating. However, problems existed with both those methods of reactivating the dessicant.
As my aforementioned patent went on to describe, electrical heating required a large amount of electric power, which many damaged buildings would not have available. Utilizing alternatively provided generators, on the other hand, added additional expense from their rental, along with an accompanying high fuel bill. Propane fuel dehumidifiers, moreover, exhibited many disadvantages of their own: a) Special permits were frequently required to transport the propane to the work site by trailer or other vehicle; b) Additional permits were oftentimes required for working with propane at the work site itself; c) A resupply of propane may not be readily available—as where the building being dried was at a remote location or when a resupply was needed in the middle-of-the-night, or on a Sunday; d) Firing the dehumidifier with propane produced a moisturizing effect which undesirably wetted the processed air being dried; and e) Propane, itself, was highly flammable.
My patent recognized the need to rapidly dehumidify water-logged buildings and their contents by recirculating air between the building involved and equipment employed—with the air being ducted from the building through the equipment (which absorbs moisture from the air to lower its humidity), and with the dried air being routed back into the building where it absorbs additional moisture from the surrounding air in the building and the building contents. Also recognizing that the recirculation process needs to be carried out continuously, 24 hours a day, until the building interior is determined to be sufficiently dry, such drying process needs to continue for a number of days—especially where a structure such as a hotel or office building has been damaged by water due to a storm or the extinguishment of a fire. However, in order for the dessicant to keep absorbing water, my patent further recognizes that the dessicant must be continuously heated to evaporate the water that it has absorbed. Thus, the equipment employed required an energy source or sources to (i) drive a processed air blower to recirculate air to and from the drying equipment and the building, (ii) drive a reactivation blower to direct heated ambient air through the dessicant, and (iii) heat the ambient air prior to its passing through the dessicant. For a hotel, office building, or other typical commercial building, relatively large amounts of energy continued to be required to heat the ambient air so as to keep the dessicant sufficiently dry—due to the high volumetric rates of air flow involved (measured in cubic feet per minutes).
As described in my issued patent, on the other hand, such firing of the heat exchanger to heat the air for evaporating moisture from the dessicant forswore the use of electric heaters or propane burners as previously employed, and proceeded by the burning of diesel fuel—or its equivalent of kerosene or No. 1 or No. 2 fuel oil. As there set out, the diesel fuel thus employed in the heating process was available virtually anywhere where diesel trucks served as a means of transportation. Because diesel fuel provided a greater amount of BTU's per gallon than propane, less fuel was required to provide the heat for the dessicant than with propane, resulting in a cost savings in use. Also, because such fuel burned without producing moisture, the processed air became that much drier, enabling the reactivation of the dessicant to be accomplished faster, thereby increasing performance in operation. And, because the dessicant dehumidifier of the invention operated more efficiently, its construction allowed for a reduction in the required horsepower of the reactivation blower pulling the ambient air over the heat exchanger—resulting in a more compact machine, for easier transportation.